1. Field of the Invention
The present invention relates to a stator of a rotary electric machine to be mounted in a vehicle such as a passenger car or a truck.
2. Description of the Related Art
A stator of a rotary electric machine such as a motor or a generator includes a stator core having plural slots. Laid-open patent publications WO92/06527 and JP-A-2003-199304, or its counterpart US 2003/0121139 A1 disclose stators having plural slots in which U-shaped conductor segments are inserted.
The stator disclosed in WO92/06527 has irregular U-shaped conductor segments besides regular U-shaped conductor segments, which are welded to one another to form a stator winding. When the stator winding is formed, the turn portion of the irregular U-shaped conductor segments are twisted by a twisting ring. Therefore, it is necessary for the turn portions of the irregular U-shaped conductor segments to have certain height from an axial end of the stator core. In other words, the irregular U-shaped conductor segments increases resistance of the stator winding.
The stator disclosed in US 2003/0121139 A1 also has irregular U-shaped conductor segments to connects the regular U-shaped conductor segments. These irregular U-shaped conductor segments are formed to have an S-shaped meander on the top of the turn portions to connect the regular U-shaped conductor segments. That is, the S-shaped meander increases the length and the resistance of the stator winding.